Disc device with a turntable being able to extend into an opening in a top plate connected to a lid

ABSTRACT

A disc device has a movable mechanism used for moving a carriage carrying a disc so that the carriage either projects from an apparatus or is inserted into the apparatus. The disc carried by the carriage is exposed for an operator to handle the disc when the carriage projects from the apparatus. The disc carried by the carriage is contained in the apparatus after the carriage has been inserted into the apparatus. A rotating unit rotates the disc carried by the carriage and an accessing unit accesses the disc carried by the carriage. The disc device is incorporated into the apparatus. A locking mechanism locks the carriage in the apparatus, and a releasing unit causes the locking mechanism to release locking of the carriage in the apparatus. The releasing unit causes the rotating unit to stop rotating of the disc and also causes the accessing unit to stop accessing the disc, prior to each time the releasing unit causes the locking mechanism to release locking of the carriage in the apparatus. The locking mechanism is contained in the carriage.

This is a divisional application of a copending application Ser. No.09/158,638, filed Sep. 22, 1998, which is a divisional application of acopending application Ser. No. 08/972,223, filed Nov. 17, 1997, U.S.Pat. No. 5,878,012, which is a divisional application of a copendingapplication Ser. No. 08/831,857, filed Apr. 2, 1997, U.S. Pat. No.5,862,116, which is a continuation application now abandoned, Ser. No.08/392,365 filed Feb. 22, 1995.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to a disc device, in particular, to a discdevice having a part containing a disc, which part can be drawnfrom/inserted in to the disc device. One example of such a disc deviceis a CD-ROM drive device which may be incorporated into a notebook typepersonal computer or the like.

2. Description of Related Art

A compact disc, having a diameter of 12 cm or 8 cm, serving as aninformation recording medium, has been being used for recording, forexample, data base, software program or the like. Such informationrecorded on a compact disc will be reproduced using a laser type pickup. The above-mentioned CD-ROM drive device is used to handle thecompact disc used as a ROM. Such a compact disc is called a CD-ROM. TheCD-ROM drive device has been developed to be incorporated into anotebook type personal computer. The notebook type personal computer isa miniaturized personal computer. In the above-mentioned development,the CD-ROM drive device is developed to be incorporated into a givencase.

One example of such a CD-ROM drive device in the related artincorporated into a notebook type personal computer or the like will nowbe described. A CD-ROM drive body of the CD-ROM drive device iscontained in a containing portion formed in a personal computer body.When the CD-ROM is loaded on the CD-ROM drive body or a once loadedCD-ROM is removed from the CD-ROM drive body, the CD-ROM drive bodyitself is drawn from the personal computer body.

A push-on/push-off mechanism is used between the CD-ROM drive device andthe above-mentioned containing portion formed in the personal computerbody. By using the push-on/push-off mechanism, the CD-ROM drive body canbe locked in the containing portion when an operator pushes the CD-ROMdrive body. Further, the locking of the CD-ROM drive body in thecontaining portion can be released so that the CD-ROM drive body can bedrawn from the personal computer, when the operator pushes the CD-ROMdrive body. If the CD-ROM drive body can be drawn from the containingportion at any time, a problem may occur. That is, if the CD-ROM drivebody is drawn from the containing portion, that is, it is drawn from thepersonal computer, during the CD-ROM being rotated by means of a spindlemotor and/or an optical head accessing the CD-ROM, an operator's handmay, by accident, touch the CD-ROM being rotated.

In order to eliminate such a problem, a locking mechanism having anelectrically operating interlocking function has been used instead ofthe above-described push-on/push-off mechanism. If such a lockingmechanism is used, an operator performs an ejecting operation. As aresult of the ejecting operation being performed, the rotation of theCD-ROM is stopped and also the optical head is removed from the CD-ROM.The above-mentioned locking of the CD-ROM drive body in the containingportion is then released after the rotation of the CD-ROM has beenstopped and also the optical head has been removed from the CD-ROM.

With reference to FIG. 1, the CD-ROM drive device 81 in the related arthaving such a locking mechanism will now be described. The CD-ROM drivedevice 81, due to the locking mechanism, releases the locking of theCD-ROM drive body in the containing portion after an operation in theCD-ROM drive device has been stopped. The CD-ROM drive device 81includes the flat rectangular parallelopiped CD-ROM drive body 82. TheCD-ROM drive body 82 has a turn table 83, a spindle motor (not shown inthe figure) for rotating the turn table 83, the optical head 84, anoptical head moving mechanism (not shown in the figure) and so forthprovided therein. Further, a locking mechanism 91 for locking the CD-ROMdrive body 82 in the containing portion 73 and releasing the locking isprovided in the CD-ROM drive device 81.

The CD-ROM drive body 82 is slidable along directions A₁ (reardirection) and A₂ (front direction) shown in FIG. 1 with respect to thecontaining portion 73 formed in the personal computer body 71. FIG. 1shows a state where the CD-ROM drive body 82 is contained in thecontaining portion 73. A front panel 85 is provided in front of theCD-ROM drive body 82 as shown in the figure. In this state, the frontend of the front panel 85 is approximately aligned with a front surfaceof the personal computer body 71 along a direction perpendicular to thedirections A₁ and A₂.

The locking mechanism 91 is consists of a plunger 92, a locking arm 94and a spring 95, they being located at a rear portion of the containingportion 73, and a locking pin 97 formed on the CD-ROM drive body 82.When no electric current is supplied to the plunger 92, the locking arm94 is forced to turn about a shaft S counterclockwise in the figure bymeans of the spring 95. An iron core 93 provided as a part of theplunger 92 is movable along directions E₁ and E₂ shown in the figure.When an electric current is supplied to the plunger 92, the iron core 93is forced to move in the direction E₂ as a result of an electric magnetprovided in the plunger 92 attracting the iron core 93.

In a state where the CD-ROM drive body 82 is contained in the containingportion 73, no electric current is supplied to the plunger 92.Therefore, an end portion 94a of the locking arm 94 engages with thelocking pin 97 as shown in FIG. 1. Thus, the CD-ROM drive body 82 islocked in the containing portion 73 and thus the CD-ROM drive body 82cannot be drawn in the direction A₂.

When the ejecting operation is performed by the operator, an electriccurrent is supplied to the plunger 92 and thus the electric magnet ofthe plunger 92 attracts the iron core 93 in the direction E₂, the ironcore 93 thus moving in the direction. As a result, a projecting end ofthe iron core 93 pushes a end portion 94b of the locking arm 94 and thusthe locking arm 94 is rotated clockwise. Thereby, the end portion 94a isremoved from the locking pin 97 and thus the locking of the CD-ROM drivebody 82 in the containing portion 73 is released. A pushing mechanism(not shown in the figure) then pushes the CD-ROM drive body 82 in thedirection A₂ for a predetermined stroke. Thus, the operator may pull thefront panel 85 of the CD-ROM drive body 82 and draw the CD-ROM drivebody 82 from the containing portion 73 in the direction A₂.

In order to make the thus-drawn CD-ROM drive body 82 again be containedin the containing portion 73, an operator may push the CD-ROM drive body82 in the direction A₁. Thus, the end portion 94a of the locking arm 94engages with the locking pin 97 and thus the CD-ROM drive body 82 isagain locked in the containing portion 73.

A CD-ROM drive device 100 in another example in the related art beingprovided with a locking mechanism 101 including a motor 102 and a groupof cams 103 will now be described, with reference to FIG. 2. The samereference numerals, as those of the components in the CD-ROM drivedevice 81 shown in FIG. 1, are given to components in the CD-ROM drivedevice 100 identical to the components in the device 81.

The locking mechanism 101 includes the motor 102, the group of cams 103,a locking arm 104 and a spring 106. The locking pin 97 is formed on theCD-ROM drive body 82. When no electric current is supplied to the motor102, the locking arm 104 is formed to be rotated about a shaft 105clockwise by means of the spring 106.

In a state where the CD-ROM drive body 82 is contained in the containingportion 73, no electric current is supplied to the motor 102. Therefore,an end portion 104a of the locking arm 104 engages with the locking pin97 as shown in FIG. 2. Thus, the CD-ROM drive body 82 is locked in thecontaining portion 73 and thus the CD-ROM drive body 82 cannot be drawnin the direction A₂.

When the ejecting operation is performed by the operator, an electriccurrent is supplied to the motor 102 and thus the motor 102 rotates camgears 103b and 103a. As a result, a cam pin 107 presses an end portion104b of the locking arm 104. Thus, the locking arm 104 is rotatedcounterclockwise. Thereby, the end portion 104a is removed from thelocking pin 97 and thus the locking of the CD-ROM drive body 82 in thecontaining portion 73 is released. A pushing mechanism (not shown in thefigure) then pushes the CD-ROM drive body 82 in the direction A₂ for apredetermined stroke. Thus, the operator may pull the front panel 85 ofthe CD-ROM drive body 82 and draw the CD-ROM drive body 82 from thecontaining portion 73 in the direction A₂.

However, either of the CD-ROM drive devices in the related art shown inFIGS. 1 and 2 needs a space for containing the locking mechanism 91 or101 behind the CD-ROM drive body 82. Thereby, miniaturizing of theCD-ROM drive device including the containing portion 73 and thinning ofthe CD-ROM drive device is limited. From another point of view, if theentire volume of the CD-ROM drive device is fixed, such a space forcontaining the locking mechanism 91 or 101 restricts a space requiredfor containing other attachments of the CD-ROM drive device such as anelectric circuit substrate, a flexible wire and so forth.

With reference to FIGS. 3, 4 and 5, a CD-ROM drive device 161 in anotherexample in the related art will now be described. FIG. 4 shows a frontelevational view of the device 161 but a front panel 172 is omitted inFIG. 4. FIG. 5 shows a left side elevational view of the device 161. TheCD-ROM drive device 161 includes a containing portion 162 fixed in apersonal computer body and a CD-ROM drive body 171 movable with respectto the containing portion 162 along directions A₁ and A₂ shown in FIGS.3 and 5.

The CD-ROM drive body 171 includes a flat rectangular parallelopipedhousing 173. The housing 173 has the turn table 185, the spindle motor(not shown in the figure) for rotating the turn table 185, the opticalhead 186, the optical head moving mechanism (not shown in the figure)and so forth provided therein. The housing 173 further has the frontpanel 172 fixed thereon. Further, the locking mechanism for locking theCD-ROM drive body 171 in the containing portion 162 and releasing thelocking is provided in the CD-ROM drive device 161. The lockingmechanism used in the device 161 comprises, for example, theabove-described push-on/push-off mechanism.

A top plate 173a of the housing 173 has an opening 173d formed therein.The turn table 185 projects from a top surface 173a through the opening173d as shown in FIG. 3, the CD-ROM 51 being placed on the turn table185. The optical head 186 is exposed via the opening 173d as shown inFIG. 3, the optical head 186 directing upward.

Side plates 164 and 165 have rail members 181 and 182 fixed thereonrespectively. Each of the rail members 181 and 182 extends along thedirections A₁ and A₂ and has an angular letter "C"-shaped section asshown in FIG. 4. Side plates 173b and 173c of the housing 173 of theCD-ROM drive body 171 have guides 175 and 176 formed thereonrespectively. Each of the guides 175 and 176 is shaped so that asectional view thereof includes a protrusion which is fitted into agroove formed on a respective one of the rail members 181 and 182 asshown in FIG. 4. The thus-shaped guides 175 and 176 are slidable on therail members 181 and 182 respectively in a state in which theprotrusions of the guides 175 and 176 are fitted into the grooves of therail members 181 and 182 respectively.

As the guides 175 and 176 being guided by the rail members 181 and 182respectively, the CD-ROM drive body 171 is movable with respect to thecontaining portion 162 along the directions A₁ and A₂. FIG. 3 shows astate in which the CD-ROM drive body 171 has been drawn from thecontaining portion 162 to the limit.

In a state in which the CD-ROM drive body 172 is contained in thecontaining portion 162, the locking mechanism locks the CD-ROM drivebody 171 in the containing portion 162. Thus, drawing of the CD-ROMdrive body 171 in the direction A₂ is prevented. In this state, theprotrusions of the guides 175 and 176 are fitted into the grooves of therail members 181 and 182 through the entire length thereof along thedirections A₁ and A₂.

When the ejecting operation is performed by an operator, the locking ofthe CD-ROM drive body 171 in the containing portion 162 performed by thelocking mechanism is released. After that, the operator may draw theCD-ROM drive body 171 from the containing portion 162 in the directionA₂ by pulling the front panel 172. As shown in FIGS. 3 and 5, in thestate where the CD-ROM drive body 171 has been drawn from the containingportion 162 to the limit, the protrusions of the guides 175 and 176engage with the grooves of the rail members 181 and 182 for a length ofL₁ along the directions A₁ and A₂ shown in the figures at the rear endof the CD-ROM drive body 171.

In the CD-ROM drive device 161 in the related art shown in FIGS. 3, 4and 5, a length along the directions A₁ and A₂ for which the protrusionsof the guides 175 and 176 engage with the grooves of the rail members181 and 182 becomes shorter as the CD-ROM drive body 171 is drawn fromthe containing portion 162. Dimensions of the CD-ROM drive body 171 andthose of the containing portion 162 are the minimum ones in order tominiaturize the CD-ROM drive device 161. As a result, theabove-mentioned engaging length L₁ shown in FIGS. 3 and 5 is inevitablyshortened to be approximately 10% of the entire length of each of theguides 175 and 176.

Further, there are appropriate clearances between each of the guides 175and 176 and a respective one of the rail members 181 and 182 such thatthe CD-ROM drive body 171 is slidable in the containing portion 162along the directions A₁ and A₂. By these clearances, the CD-ROM drivebody 171 may undesirably move with respect to the containing portion 162along directions other than along the directions A₁ and A₂. Lengths ofsuch possible undesirable movement increase as the length in thedirections A₁ and A₂ for which the guides 175 and 176 engage with therail members 181 and 182 is shortened.

That is, the lengths of such possible undesirable movement increase asthe CD-ROM drive body 171 is drawn from the containing portion 162 tothe limit. The possible undesirable movement has the maximum movinglengths when the CD-ROM drive body 171 has been drawn from thecontaining portion 162 to the limit. The possible undesirable movementincludes movement in vertical directions Z₁ and Z₂ shown in FIGS. 4 and5 and movement in horizontal directions B₁ and B₂ shown in FIGS. 3 and5. In the structure shown in FIGS. 3, 4 and 5, assuming that a drawnlength of the CD-ROM drive body 171 is 120 mm when it has been drawn tothe limit and then the above-mentioned length L₁ is 10 mm, an front endof the CD-ROM drive body 171 may move for approximately 4 mm in thevertical directions.

In a disc device, such as the CD-ROM drive device, in the related art, atray such as the CD-ROM on which a disc such as the CD-ROM is placed isdriven by a motor. When the tray has been drawn from a chassis of thedisc device, an operator may place the disc on a turn table provided inthe tray. The motor then drives the tray having the disc placed on theturn table to be returned inside the chassis. Then, the disc is clampedonto the turn table.

Such a CD-ROM drive device has the motor and a power transmissionmechanism for transmitting driving power of the motor to the trayprovided therein. Due to a space for containing the motor and the powertransmission mechanism, miniaturizing of the CD-ROM drive device andthinning of the CD-ROM drive device is limited. Therefore, it is notpossible to incorporate such a CD-ROM drive device into a notebook typepersonal computer.

In order to eliminate such a problem, a disc device, such as the CD-ROMdrive device, which does not include the motor and the powertransmission mechanism has been being developed. In such a disc device,the tray is manually moved so that either the tray is inserted in thechassis for an operator to use the disc as an information recordingmedium or the tray is drawn from the chassis for the operator to replacethe disc on the tray. A position of the tray which is obtained as aresult of the tray being inserted into the chassis so that the operatorcan use the disc as an information recording medium will be referred toas a loaded position, hereinafter. A position of the tray which isobtained as a result of the tray being drawn from the chassis so thatthe operator can replace the disc on the tray will be referred to as areplaceable position, hereinafter.

A disc device in an example in the related art such as the devicementioned above in which the tray is manually moved will now bedescribed. The tray is supported on a sub-chassis which has guide railsprovided on two sides thereof. Due to a function of the guide rails ofthe sub-chassis, the sub-chassis is movable with respect to the chassisof the disc device. Thus, the tray is movable with respect to thechassis. The turn table and a pick up are mounted to a base which ismounted to the sub-chassis. Because the turn table and the pick up areprecision components, it is necessary to prevent any vibrationsoccurring in the sub-chassis from being applied to the turn table andpick up. For this purpose, a rubber-made vibration absorbing member forabsorbing vibrations is inserted between the base and the sub-chassis.

However, in the above-described structure, because the tray is directlymounted on the sub-chassis, vibrations occurring in the sub-chassis aredirectly transmitted into the tray. Further, part of these vibrationsare also transmitted to the turn table and pick up via the vibrationabsorbing member and the base. Because the vibration absorbing member isprovided only between the sub-chassis and the base, the turn table andthe pick up vibrate periodically in a period different from a period inwhich the tray vibrates periodically. If a relatively large vibrationoccurs in the sub-chassis, the rubber-made vibration absorbing membermay be elastically deformed in a large deformation length. In such acase, the turn table and pick up may vibrate violently and thus the discclamped onto the turn table may come into contact with the tray. If thedisc come into contact with the tray, the disc may be damaged.

Similarly, due to the vibration of the turn table, the turn table maycome into contact with a top plate. The top plate is a plate which covera top side of the chassis of the disc device. The top plate is locatedover the turn table, when the tray is in the above-mentioned loadedposition. In order to prevent the turn table from coming into contactwith the top plate, it is necessary to position the top plate anappropriate clearance away from the turn table. However, this result inlimiting miniaturizing of the disc device and thinning thereof.

In a disc device in the related art, the tray has outer dimensions suchthat the entire outer diameter of the disc can be placed on the tray.Specifically, the tray has a concavity formed thereon which contains thedisc. Such a structure of the tray limits miniaturizing of the tray andthus limits miniaturizing of the disc device.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a disc device in whicha space for the locking mechanism, such as the above-mentioned mechanism91 or 101, is not needed behind a carriage such as the CD-ROM drive body82. Thus, miniaturizing and thinning of the disc device can be realized.

In order to achieve the above-mentioned object, in a disc device whichis incorporated in an apparatus, disc rotation is stopped and alsoaccessing of the disc is stopped prior to a time a carriage for carryingthe disc is projected from the apparatus. That is, a locking mechanismis provided for locking the carriage in the apparatus so that thecarriage is prevented from projecting before the disc rotation isstopped and also the accessing of the disc is stopped. The lockingmechanism is contained in the carriage.

As a result, a problematic situation in which an operator's hand maycome into contact with the disc when the disc is being rotated andaccessed is avoided. Further, as a result of the locking mechanism beingcontained in the carriage, it is possible to miniaturize and thin thedisc device.

Another object of the present invention is to provide a disc device inwhich lengths of possible undesirable movement of a carriage such as theabove-mentioned possible undesirable movement of the CD-ROM drive bodycan be reduced. Thus, miniaturizing and thinning of the disc device canbe realized.

In order to achieve the above-mentioned object, a guiding mechanism isprovided for guiding the carriage to move with respect to the apparatusin a predetermined manner. The guiding mechanism includes:

a static member mounted on the apparatus and having a rack gear;

a moving member mounted on the carriage and having a rack gear;

an intermediate member being fitted to the static member and the movingmember, the intermediate member sliding on the static member and alsosliding on the moving member as the carriage moves with respect to theapparatus;

the intermediate member having a pinion gear rotatably supportedthereon, the pinion gear engaging with the rack gear of the staticmember at a first position of the pinion gear, and engaging with therack gear of the moving member at a second position of the pinion gearopposite to the first position thereof, so that the pinion gear rotatesas the intermediate member slides on the static member and also slideson the moving member.

By providing such a guiding mechanism, it is possible for, even in astate where the carriage has been projected from the apparatus to thelimit, by approximately half the length of the entire length of each ofthe static member and moving member, the intermediate member is fittedto a respective one of the static member and moving member. As a result,disadvantageous possible movement a projecting end of the carriage withrespect to the apparatus in a state where the carriage has beenprojected from the apparatus can be reduced.

Another object of the present invention is to provide a disc device inwhich undesirable vibration of the turn table is reduced. Thus,miniaturizing and thinning of the disc device can be realized.

For this purpose, in one aspect of the present invention,

a disc device comprising:

a turn table for rotating a disc;

a pick up unit for detecting information recorded in said disc;

a base for supporting said turn table and said pick up unit;

a tray, mounted on said base, for guiding an operator's placement ofsaid disc on said turn table,

wherein said operator may move said tray between a disc loading positionand a disc replacement position;

a sub-chassis for supporting said base, said sub-chassis being slidablysupported on a chassis so that said tray may move between said discloading position and said disc replacement position; and

a vibration absorbing member provided between said sub-chassis and saidbase, for elastically supporting said base and said tray.

In this structure, the vibration absorbing member elastically supportsnot only the base supporting the turn table and pick up unit but alsothe tray. Therefore, the disc clamped onto the turn table is preventedfrom disadvantageously coming into contact with the tray.

Another object of the present invention is to provide a disc device inwhich the tray can be miniaturized and thus the disc device can beminiaturized.

For this purpose, in another aspect of the present invention, a discdevice comprising:

a turn table for rotating a disc; and

a tray for guiding an operator's placement of said disc on said turntable,

said operator being able to move said tray between a disc loadingposition and a disc replacement position; and

said tray having a structure such that a part of said disc placed onsaid turn table extends from an edge of said tray.

Thus, an operator can easily hold the extending part of the disc andthus easily and surely take the disc out from the tray. Further, such astructure of the tray enables the chassis to be miniaturized and thusthe disc device to be miniaturized.

Other objects and further features of the present invention will becomemore apparent from the following detailed description when read inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a plan view of a CD-ROM drive device in an example in therelated art;

FIG. 2 shows a plan view of a CD-ROM drive device in another example inthe related art;

FIG. 3 shows a plan view of a CD-ROM drive device in still anotherexample in the related art;

FIG. 4 shows a front elevational view of the CD-ROM drive device shownin FIG. 3;

FIG. 5 shows a left side elevational view of the CD-ROM drive deviceshown in FIG. 3;

FIG. 6 shows a plan view of a CD-ROM drive device in a first embodimentof the present invention in a state in which a CD-ROM drive body iscontained in a containing portion;

FIG. 7 shows a plan view of the CD-ROM drive device shown in FIG. 6 in astate in which the CD-ROM drive body is partially contained in thecontaining portion;

FIG. 8 shows a front elevational view of the CD-ROM drive device shownin FIG. 6, and in particular shows a sliding mechanism;

FIG. 9 shows another front elevational view of the CD-ROM drive deviceshown in FIG. 6;

FIG. 10 shows a side elevational sectional view of the CD-ROM drivedevice shown in FIG. 6 viewed along a line C₁ -C₂ shown in FIG. 6;

FIG. 11 shows a perspective view of a CD-ROM drive device in a secondembodiment of the present invention;

FIG. 12 shows a plan view of the CD-ROM drive device shown in FIG. 11 ina state in which a CD-ROM drive body has been drawn from a containingportion to the limit;

FIG. 13 shows a front sectional view of the CD-ROM drive device shown inFIG. 11 viewed in a direction A₁ shown in FIG. 11;

FIG. 14 shows a right side elevational sectional view of the CD-ROMdrive device shown in FIG. 11 viewed in a direction B₁ shown in FIG. 11;

FIG. 15 shows a left side elevational view of a guiding mechanismconsisting of rail members and a coupling member of the CD-ROM drivedevice shown in FIG. 11 viewed in a direction B₂ shown in FIG. 11 in thestate in which the CD-ROM drive body has been drawn from the containingportion to the limit;

FIG. 16 shows a left side elevational view of the guiding mechanismconsisting of rail members and a coupling member of the CD-ROM drivedevice shown in FIG. 11 viewed in a direction B₂ shown in FIG. 11 in astate in which the CD-ROM drive body is contained in the containingportion;

FIG. 17 shows a front sectional view of the guiding mechanism consistingof rail members and a coupling member of the CD-ROM drive device shownin FIG. 11 viewed along a line C₁ and C₂ shown in FIG. 12;

FIG. 18 shows a perspective view of a CD-ROM drive device in a thirdembodiment of the present invention;

FIG. 19 shows a perspective view of the CD-ROM drive device shown inFIG. 18 but in which a tray has projected from a containing portion;

FIG. 20 shows an exploded perspective view of upper part of the CD-ROMdrive device shown in FIG. 18;

FIG. 21 shows an exploded perspective view of lower part of the CD-ROMdrive device shown in FIG. 18;

FIGS. 22A and 22B show a plan view and front view of the tray of theCD-ROM drive device shown in FIG. 18;

FIGS. 23A, 23B, 23C, and 23D show a sub-chassis of the CD-ROM drivedevice shown in FIG. 18;

FIG. 24 shows a plan view of the CD-ROM drive device shown in FIG. 18 inwhich two sides of the sub-chassis are supported by two guide railmechanisms respectively;

FIG. 25 shows a sectional front elevational view of the CD-ROM drivedevice shown in FIG. 18 illustrating the guide rail mechanisms andpulling member;

FIG. 26 shows a side elevational view of the guide rail mechanism whenthe tray has been contained in the containing portion;

FIG. 27 shows a side elevational view of a guide rail mechanism when thetray has projected from the containing portion;

FIGS. 28A, 28B, and 28C are magnified views of the guide rail mechanismand pulling member;

FIG. 29 shows a plan view of the CD-ROM drive device shown in FIG. 18 ina state in which a top plate has been removed;

FIG. 30 shows a side elevational view of the CD-ROM drive device shownin FIG. 18 in a state in which a base and the tray are mounted on thesub-chassis;

FIGS. 31A and 31B show a plan view and a front view of the base of theCD-ROM drive device shown in FIG. 18;

FIGS. 32A and 32B show a side elevational view and a bottom view of thebase of the CD-ROM drive device shown in FIG. 18;

FIG. 33 shows a sectional side elevational view of a vibration absorbingmember provided between the base and the sub-chassis of the CD-ROM drivedevice shown in FIG. 18;

FIG. 34 shows a sectional elevational view of the CD-ROM drive deviceshown in FIG. 18, illustrating special relationship between the tray, aturn table, the top plate and a lid;

FIG. 35 shows a plan view of the lid closing an opening formed in thetop plate of the CD-ROM drive device shown in FIG. 18;

FIG. 36 shows a sectional side elevational view of the CD-ROM drivedevice shown in FIG. 18 illustrating a spatial relationship between theturn table, the top plate and the lid, in a state in which the tray isin a disc loading position;

FIG. 37 shows a sectional side elevational view of the CD-ROM drivedevice shown in FIG. 18 illustrating a spatial relationship between theturn table, the top plate and the lid, in a state in which the tray ismoving in a direction A from the disc loading position;

FIG. 38 shows a plan view of the CD-ROM drive device shown in FIG. 18 inwhich a part of the tray is eliminated from being shown;

FIGS. 39A and 39B are magnified sectional side elevational views of afirst holding member;

FIGS. 40A, 40B and 40C show magnified plan views of a second holdingmember;

FIG. 41 shows a magnified plan view of a locking lever in the CD-ROMdrive device shown in FIG. 18; and

FIG. 42 shows a plan view of the CD-ROM drive device shown in FIG. 18 inwhich a part of the tray is eliminated from being shown, in a state inwhich the tray is in a disc replacement position.

DESCRIPTION OF PREFERRED EMBODIMENTS

With reference to FIGS. 6, 7, 8, 9 and 10, a CD-ROM drive device 21 in afirst embodiment of the present invention will now be described. FIG. 6shows a state in which a CD-ROM drive body 22 is contained in and hasbeen locked in a containing portion 13. FIG. 7 shows a state in whichthe body 22 has been intermediately inserted into the containing portion13 and has not been locked in the containing portion 13.

In FIG. 8, indicating of a front panel is omitted and thus a slidingmechanism for making the CD-ROM drive body 22 be slidable with respectto the containing portion 13 is indicated.

The CD-ROM drive device 21 includes the CD-ROM drive body 22 having aflat rectangular parallelopiped shape. The CD-ROM drive body 22 isprovided with a turn table 31, a spindle motor 35 for rotating the turntable 31, an optical head 32, guide shafts 33 and 34 for guidingmovement of the optical head 32, an optical head moving mechanism (notshown in the figures), and so forth. The CD-ROM drive body 22 isslidable along directions A₁ and A₂, shown in FIGS. 6, 7 and 10, withrespect to the containing portion 13 formed in a personal computer body11. An opening 23a is formed in a top plate 23 of the CD-ROM drivedevice 22. Through the opening 23a, the turn table 31 projects upwardand also the optical head 32 is exposed.

A lock mechanism 41 is provided inside the CD-ROM drive body 22. Thelocking mechanism 41 locks the CD-ROM drive body 22 in the containingportion 13 and releases the locking. A pushing mechanism 56 is providedat a rear end of the CD-ROM drive body 22. The pushing mechanism 56pushes the CD-ROM drive body 22 so as to move it forward in thedirection A₂ with respect to the containing portion 13.

In FIGS. 6 and 10, the CD-ROM drive body 22 is in a state in which theCD-ROM drive body 22 is contained in the containing portion 13. In thisstate, the front panel 27 provided in front of the CD-ROM drive device22 is located so that a front surface of the front panel 27 isapproximately aligned with a front surface 12 of the personal computerbody 11 along a direction perpendicular to the directions A₁ and A₂.

As shown in FIG. 8, the sliding mechanism of the CD-ROM drive device 22includes guiding protrusions 24b and 25b protrude from side plates 24and 24 respectively of the CD-ROM drive body 22. Each of the guidingprotrusions 24b and 25b is formed as a result of forming grooves 24a and25a and extends along the directions A₁ and A₂. The sliding mechanismalso includes rails 67 and 68 mounted on side walls 15 and 16respectively of the containing portion 13. Each of the rails 67 and 68has a sectional view of an angular letter "C" as shown in FIG. 8 andextends along the directions A₁ and A₂. Each of the guiding protrusions24b and 25b loosely is fitted to a concavity of a respective one of therails 67 and 68 so that the CD-ROM drive body 22 is slidable withrespect to the containing portion 13 in the directions A₁ and A₂ as theguiding protrusions 24b and 25b are guided by the rails 67 and 68.

The locking mechanism 41 is provided at a front space inside the CD-ROMdrive body 22. The locking mechanism 41 includes a locking arm 42supported by the shaft 43 formed in the CD-ROM drive body 22, the arm 42being thus rotatable about the shaft 43. The mechanism 41 furtherincludes a spring 49 which is provided between the locking arm 42 and aspring holding portion 50 formed in the CD-ROM drive body 22. Themechanism 41 further includes a plunger 45 for rotating the locking arm52.

When no electric current is supplied to the plunger 45, the locking arm42 is forced to turn about the shaft 43 counterclockwise in FIGS. 6 and7 by means of the spring 49. Therefore, a end portion 42c of the lockingarm 42 comes into contact with a stopper 48 which is formed in theCD-ROM drive body 22. An iron core 47 provided as a part of the plunger45 is movable along directions B₁ and B₂ shown in the figures withrespect to a plunger body 46 of the plunger 45. When an electric currentis supplied to the plunger 92, the iron core 93 is forced to move in thedirection B₂ as a result of an electric magnet provided in the plunger92 attracting the iron core 93.

A locking pin 55 is formed on a bottom 17 of the containing portion 13,the pin 55 being used so that locking arm 42 of the locking mechanism 41engages the pin 55 and thus the CD-ROM drive body 22 is locked in thecontaining portion 13 as shown in FIG. 6. An appropriate opening isformed in a bottom plate 28 of the CD-ROM drive body 22 such that thelocking pin 55 is prevented from coming into contact with the bottomplate 28 while the CD-ROM drive body 22 moves in the containing portion13. The locking pin 55 projects inside the CD-ROM drive body 22 throughthe opening when a certain length of the CD-ROM drive body 22 iscontained in the containing portion 13. As shown in FIG. 6, in a statein which the CD-ROM drive body 22 is contained in the containing portion13, an engaging portion 42a of the locking arm 42 engages with thelocking pin 55 and thus the CD-ROM drive body 22 is locked in thecontaining portion 13.

Thus, the locking mechanism 41 has a simple structure consisting of thelocking arm 42, plunger 45 and spring 49.

As shown in FIGS. 6 and 7, the pushing mechanism 56 includes a slidinglever 57, and a spring 60 which is provided between a spring holdingportion 61 provided in the CD-ROM drive body 22 and an end portion 57dof the sliding lever 57. Pins 58 and 59 fixed on a rear surface of thetop plate 23 of the CD-ROM drive device 22 are fitted into long holes57b and 57c respectively. The long holes 57b and 57c are formed in thesliding lever 57. Because the pins 58 and 59 can move inside the longholes 57b and 57c respectively, the sliding lever 57 can move in thedirections A₁ and A₂ with respect to the CD-ROM drive body 22. Thesliding lever 57 is forced to move the direction A₁ by means of thespring 60. As shown in FIG. 10, the sliding lever 57 projects backwardin the direction A₁ from a rear plate 26 of the CD-ROM drive body 22. Aprojecting end portion 57a of the sliding lever 57 comes into contactwith a contact portion 18a of a rear wall 18 of the containing portion13 when the CD-ROM drive body 22 is contained in the containing portion13.

Performance of the CD-ROM drive device 21 will now be described. Thedescription to be made is description of the performance executed whenthe CD-ROM drive body 22 is being contained in the containing portion 13and is moving so as to project forward from the front surface 12 of thepersonal computer body 11.

In the state in which the CD-ROM drive body 22 is contained in thecontaining portion 13, no electric current is supplied to the plunge 45of the locking mechanism 41. Therefore, the engaging portion 42a of thelocking arm 42 engages with the locking pin 55, and thus the CD-ROMdrive body 22 is locked so as to be prevented from being drawn forwardin the direction A₂. In this time, the end 57a of the sliding lever 57has come into contact with the contact portion 18a of the containingportion 13 and thus the sliding lever has moved in the A₂ direction, thespring 60 being in its expanded state.

When an operator presses an ejecting switch 65 provided on the frontpanel 27 as shown in FIGS. 6, 7 and 9, a control unit (not shown in thefigures) of the CD-ROM drive device 21 detects this pressing operationand then causes the spindle motor 35 to stop and the optical head toremove from the CD-ROM placed on the turn table 31.

The control unit then supplies an electric current to the plunger 45 foran appropriate duration. Thus, the plunger 45 causes the iron core 47 tomove in the direction B₂. Thus, the end portion 47a of the iron core 47comes into contact with the end portion 42c of the locking arm 42. As aresult, the locking arm 42 is rotated clockwise about the shaft 43.Thereby, the engaging portion 42a is disengaged from the locking pin 55and thus the locking of the CD-ROM drive body 22 in the containingportion 13 is released.

As a result of the releasing the locking, an elastic shrinkage force ofthe spring 60 of the pushing mechanism 56 causes the CD-ROM drive body22 to move forward in the direction A₂ for a predetermined length. Theabove-mentioned elastic shrinkage force of the spring 60, is created asa result of the spring 60 having been expanded when the CD-ROM drivebody 22 was contained in the containing portion 13. The electricshrinkage force of the spring 60 is a force to shorten a distancebetween the end portion 57d of the sliding lever 57 and the springholding portion 61. The above-mentioned movement of the CD-ROM drivebody 22 with respect to the containing portion 13 is performed as theguiding protrusions 24b and 25b are guided by the concavities of therails 67 and 68.

After the above-mentioned appropriate duration has elapsed, supply ofthe electric current to the plunger 45 is stopped and thus a forcecausing the iron core 47 to move in the direction B₂ is canceled. As aresult locking arm 42 is rotated counterclockwise by means of the spring49 and thus is returned into a previous state as shown in FIG. 7.

Thus, the operator can handle the front panel 27 of the CD-ROM drivebody 22 which has moved forward for the predetermined length asmentioned above. The operator thus may draw the CD-ROM drive body 22forward to the limit and thus either may pick up the CD-ROM placed onthe turn table 31 or may place a desired CD-ROM on the turn table 31.

In order to make the CD-ROM drive body 22, which has been drawn forwardto the limit, come to be contained in the containing portion 13, theoperator may press the CD-ROM drive body 22 in the direction A₁ into thecontaining portion 13. By this pressing operation, the CD-ROM drive body13 is inserted into the containing portion 13 and thus enters into astate immediately before the state shown in FIG. 6 in which of theCD-ROM drive body 13 is completely contained in the containing portion13. In the state immediately before the state shown in FIG. 6, anoblique portion 42b located at a extending end of the locking arm 42comes into contact with the locking pin 55. When the operator furtherpresses the CD-ROM drive body 22 in the direction A₁, the obliqueportion 42b slides on the locking pin 55 and thus the locking lever 42is rotated clockwise. Thus, the contact between the locking lever 42 andthe locking pin 55 does not prevent the CD-ROM drive body 22 from beingfurther inserted. As a result of the CD-ROM drive body 22 being furtherinserted, the engaging portion 42a engages with the locking pin 55 asshown in FIG. 6. Thus, the CD-ROM drive body 22 is locked in thecontaining portion 13 and thus the inserting of the CD-ROM drive body 22into the containing portion 13 is completed.

If the CD-ROM (not shown in the figures) was placed on the turn table 31when the CD-ROM drive body 22 was in the state in which the CD-ROM drivebody 22 had been drawn in the direction A₂ to the limit, the CD-ROM islocated in a certain position after the CD-ROM drive body 22 has beencompletely contained in the containing portion 13. This certain positionis a position on the turn table 31 and between the top plate 23 of theCD-ROM drive body 22 and a ceiling 14 of the containing portion 13.

In the CD-ROM drive device 21 in the embodiment of the presentinvention, as described above, the locking mechanism 41 electricallycontrolled by the control unit is provided. Thereby, when the CD-ROMdrive body 22 will be drawn, that is, will project from the personalcomputer body 11, the rotation of the turn table 31 is previouslyautomatically stopped and the optical head 32 is previouslyautomatically removed from the CD-ROM placed on the turn table 31. Then,the locking mechanism is automatically operated and thus locking of theCD-ROM drive body 22 in the containing portion 13 by means of thelocking pin 55 and locking lever 42 is released. Therefore, theabove-mentioned problem can be eliminated, the problem being one that ahand or the like of the operator might come into contact with the CD-ROMduring the rotation thereof if the CD-ROM drive body 22 projected duringthe rotation of the CD-ROM.

Further, the locking mechanism 41 is provided in a space inside theCD-ROM drive body 22. Therefore, no extra space is required outside theCD-ROM drive body 22 in the containing portion 13 particularly forcontaining the locking mechanism 41. Further, it is preferable that thespace for containing the locking mechanism 41 is created as a result ofusing a free space unexpectedly formed in the body 22 during designingthe CD-ROM drive body 22. If such creation of the space is possible, itis not necessary to increase outer dimensions of the CD-ROM drive body22 particularly for containing the locking mechanism 41. As a result,miniaturization and thinning of the CD-ROM drive device 21 including thecontaining portion 13 can be achieved. Thereby, miniaturization andthinning of the personal computer body 11 can also be achieved.

Further, because no extra space is required outside the CD-ROM drivebody 22 in the containing portion 13 particularly for containing thelocking mechanism 41 as mentioned above, arrangement of otheraccessories of the CD-ROM drive device 21 such as an electric circuitsubstrate, a flexible electric wire and so forth is easy.

A prime mover in the locking mechanism 41 is not limited to the plunder45. For example, a combination of a motor and cam gears can also be usedas the prime mover in the locking mechanism 41.

With regard to FIGS. 11, 12, 13 and 14, a CD-ROM drive device 111 in asecond embodiment of the present invention will now be described.

The CD-ROM drive device 111 includes a containing portion 112 fixed in apersonal computer body, and a CD-ROM drive body 121 which is movablealong directions A₁ and A₂ shown in the figures with respect to thecontaining portion 112.

A housing of the CD-ROM drive body 121 includes a flat lid-lessbox-shaped frame 123, a top plate 124 fixed on the frame 123, a frontpanel 122 fixed on the frame 123 and the top plate 124.

A spindle motor 152 is provided in the frame 123 together with a turntable which is rotated by the turn table 123. Further, an optical head126, an optical head moving mechanism (not shown in the figures), guideshafts 127 and 128 for guiding movement of the optical head 126, and soforth are provided in the frame 123. An opening 124a is formed in thetop plate 124 through which the turn table 125 projects from the topplate 124 and the optical head 126 is exposed as shown in FIG. 11.

A locking mechanism 141 including plunger body 146 is provided at afront space on a bottom plate 123a of the frame 123. Because the lockingmechanism 141 is located near the front end of the CD-ROM drive body 121as shown in FIG. 12, a spatial arrangement of other parts/componentsprovided in the CD-ROM drive body 121 is not much adversely affected bythe presence of the locking mechanism 141. The locking mechanism 141includes a locking arm 142 rotatably supported on the bottom plate 123aby means of a shaft 143, a spring 149 provided between the locking arm142 and the bottom plate 123a, and a plunger 145.

When no electric current is supplied to the plunger 145, a force isapplied to the locking arm 142 by means of the spring 149 such that thelocking arm 142 is rotated counterclockwise about the shaft 143 and thenkeeps a state shown in FIG. 12. An iron core 147 of the plunger 145 ismovable with respect to the plunger body 146 and is attracted into theplunger body 146 when an electric current is supplied to the plunger145.

The containing portion 112 has an approximately flat lid-less box-likeshape. A pin 155 projects from a bottom 117 of the containing portion112. The locking mechanism 141 uses the pin 155. A arm portion 142a ofthe locking arm 142 is present below the bottom plate 123a of the frame123 as shown in FIG. 14. The locking arm 142 juts from a space presenton the bottom plate 123a to a space present below the bottom plate 123athrough an opening (not shown in the figures) formed in the bottom plate123a. When the CD-ROM drive body 121 is contained in the containingportion 112, a engaging portion 142a₁, which is provided at an endportion of the arm portion 142a of the locking arm 142, engages with thepin 55 as shown in FIG. 14. Thus, the CD-ROM drive body 121 is locked inthe containing portion 112.

A pushing mechanism (not shown in the figures) is provided at a portionin the vicinity of a rear end of CD-ROM drive body 121. The pushingmechanism pushes the CD-ROM drive body 121 contained in the containingportion 112 so as to move the CD-ROM drive body 121 forward in thedirection A₂.

First rail members 133 and 134 extending along the directions A₁ and A₂are fixed on side walls 118 and 114 of the containing portion 112respectively. Each of the rail members 133 and 134 has an approximatelyangular letter "C" shaped sectional view as shown in FIG. 13. Secondrails member 131 and 132 extending also along the directions A₁ and A₂are fixed on side walls 123b and 123c of the frame 123 of the CD-ROMdrive body 121 respectively. Each of the rails member 131 and 132 alsohas an approximately angular letter "C" shaped sectional view as shownin FIG. 13.

Further, a coupling member 135, consisting of a first sliding portion135a, a second sliding portion 135b and an intermediate portion 135e, isprovided between the first rail member 133 and the second rail member131 as shown in FIG. 13. Similarly, a coupling member 136, consisting ofa first sliding portion 136a, a second sliding portion 136b and anintermediate portion 136e, is provided between the first rail member 134and the second rail member 132 as shown in FIG. 13.

With reference to FIGS. 15, 16 and 17, performance of theabove-mentioned first and second rails members 133, 134, 131 and 132,and coupling members 135 and 136 will now be described. In FIG. 15, forsimplifying the description, indicating of a part of the sliding portion136a of the coupling member 136 is omitted, the part of the slidingportion 136a being a part, behind which the rail member 132 is presentin FIG. 15.

As shown in FIG. 17, the rail member 134 has a top edge portion 134dextending downward and a bottom edge portion 134e extending upward. Atop end of the bottom edge portion 134e has a rack 134a formed thereonacting a rack gear of a well-known rack and pinion engagement. The railmember 134 has a length along the directions A₁ and A₂ approximatelyreaching an entire length of the side wall 114 of the containing portion112 as shown in FIG. 12. Thus, a front end 134b of the rail member 134is aligned with a front end of the side wall 114 along a directionperpendicular to the directions A₁ and A₂. A rear end of the rail member134 approximately reaches a rear wall of the containing portion 112.

As shown in FIG. 17, the rail member 132 has a top edge portion 132dextending downward and a bottom edge portion 132e extending upward. Abottom end of the top edge portion 132d has a rack 132a formed thereonacting a rack gear of a rack and pinion engagement. The rail member 132has a length along the directions A₁ and A₂ approximately the same asthe length of the rail member 134. A rear end 132c of the rail member132 slightly projects backward from a rear end of the CD-ROM drive body121 as shown in FIG. 12. A front end of the rail member 132 reaches thefront panel 112 of the CD-ROM drive body 121.

Each of the sliding portions 136a and 136b of the coupling member 136has a plate-like shape extending along the directions A₁ and A₂. Thesliding members 136a and 136b are connected with each other via theintermediate portion 136e so that the sliding members 136a and 136b arein parallel with each other. Further, in the coupling member 136, frontends of the sliding portions 136a and 136b and the intermediate portion136e are aligned with one another along a direction perpendicular to thedirections A₁ and A₂, and also rear ends of the sliding portions 136aand 136b and the intermediate portion 136e are aligned with one anotheralong a direction perpendicular to the directions A₁ and A₂. As shown inFIGS. 12, 15 and 17, the sliding portion 136a is fitted into an insidespace of the rail member 134. This being fitted into is such that thesliding portion 136a is slidable in the rail member 134 in thedirections A₁ and A₂. For this purpose, an outer height of the slidingportion 136a measured along directions Z₁ and Z₂ shown in FIG. 17 isslightly shorter than an inner height of the rail member 134. Similarly,the sliding portion 136b is fitted into an inside space of the railmember 132. This being fitted into is such that the sliding portion 136bis slidable in the rail member 132 in the directions A₁ and A₂. For thispurpose, an outer height of the sliding portion 136b measured alongdirections Z₁ and Z₂ is slightly shorter than an inner height of therail member 132.

A length of the coupling member 136 in the directions A₁ and A₂ isslightly shorter than a length of the rail member 134. A gear 138 actingas a pinion of a rack and pinion engagement is rotatably supported onthe coupling member 136 at a position in the vicinity of the center ofthe coupling member 136. An approximate space for containing the gear138 is provided in the coupling member 136. As shown in FIGS. 16 and 17,the gear 138 engages with the rack 134a of the rail member 134 so as toform a rack and pinion engagement. Similarly, the gear 138 engages withthe rack 132a of the rail member 132 so as to form another rack andpinion engagement.

Performance of the above-mentioned rack and pinion engagements will nowbe described. As the rail member 132 moves along the direction A₁ and A₂with respect to the rail member 134, the gear 138 is rotated so as tofollow the above-mentioned movement of the rail member 132. That is, therack 132a of the rail member 132 rotates the gear 138 and the rotationof the gear 138 cause the gear to roll on the rack 134a of the railmember 134 along the directions A₁ and A₂. Because the gear 138 isrotatably supported on the coupling member 136 as mentioned above, thecoupling member 136 also moves along the directions A₁ and A₂ inresponse to the above-mentioned movement of the rail member 132.

In this performance, a moving distance of the gear 138, that is, amoving distance of the coupling member 136, along the directions A₁ andA₂, is half a moving distance of the rail member 132 with respect to therail member 134.

As shown in FIGS. 12 and 13, structure of the rail members 133, 131 andcoupling member 135 is symmetrical with the structure of the rail member134, 132 and the coupling member 136 about a symmetrical axis. Thissymmetrical axis extends at the center between a set of the members 133,131, and 135 and another set of the members 134, 132, and 136 along thedirections A₁ and A₂. Thus, performance of a combination of the railmember 133, the coupling member 135 and the rail member 131 issubstantially the same as the above-described performance of thecombination of the rail members 134, the coupling member 136 and therail member 132. Therefore, description on the set of the members 133,131 and 135 will be omitted. The rail members 131 and 132 are thuseffectively guided by the coupling members 135 and 136 and the railmembers 133 and 134. Therefore, the CD-ROM drive body 121 can smoothlyand stably move along the directions A₁ and A₂ with respect to thecontaining portion 112.

Performance of the CD-ROM drive device 111 in drawing the CD-ROM drivebody 121 in the direction A₂ and inserting it in the direction A₁ willnow be described.

FIGS. 11 and 16 show a state in which the CD-ROM drive body 121 iscontained in the containing portion 112. In this state, no electriccurrent is supplied to the plunger 145 and thus the engaging portion142a₁ of the locking arm 142 engages with the pin 155. Thus, the CD-ROMdrive body 121 is locked in the containing portion 112 and thus isprevented from being drawn in the direction A₂.

In this state, the sliding portions 136a and 136b of the coupling member136 are fitted to the rail members 134 and 132 respectively for theentire length of the coupling member 136. Therefore, the coupling member136 is almost prevented from disadvantageously moving in a certainmanner with respect to the rail member 134. The above-mentioneddisadvantageous moving in the certain manner with respect to the railmember 134 is moving in directions perpendicular to the directions A₁and A₂, in particular, is moving including inclining with respect to therail member 134. Similarly, the rail member 132 is almost prevented fromdisadvantageously moving in the certain manner with respect to thecoupling member 136. Similarly, the sliding portions 135a and 135b ofthe coupling member 135 are fitted to the rail members 133 and 131respectively for the entire length of the coupling member 135.Therefore, the coupling member 135 is almost prevented fromdisadvantageously moving in the certain manner with respect to the railmember 133. Similarly, the rail member 131 is almost prevented fromdisadvantageously moving in the certain manner with respect to thecoupling member 135. As a result, the CD-ROM drive body 121 is almostprevented from disadvantageously moving in the certain manner withrespect to the containing portion 112.

When an operator presses an ejecting button 156 provided on the frontpanel 122 shown in FIGS. 11, 12 and 14, a control unit (not shown in thefigures) provided in the CD-ROM drive device 111 detects this operator'spressing of the ejecting button 156. As a result, the control unitsupplies an electric current to the plunger 145 for an appropriateduration, which plunger 145 thus moves its iron core 147 toward theplunger body 146. Thus, the end portion 147a of the iron core 147 comesinto contact with the end portion 142c of the locking arm 142. As aresult, the locking arm 142 is rotated clockwise about the shaft 143 andthus the engaging portion 142a₁ is disengaged from the pin 155. As aresult, the locking of the CD-ROM drive body 121 in the containingportion 112 is released. The supply of the electric current to theplunger 145 is terminated and thus the locking arm 142 is rotatedcounterclockwise by means of the spring 149 so as to return to itsoriginal state.

After the locking of the CD-ROM drive body 121 has been released asmentioned above, the above-mentioned pushing mechanism pushes the CD-ROMdrive body 121 forward (in the direction A₂) for a predetermined length,as the rail members 131 and 132 of the CD-ROM drive body 121 beingguided by the coupling members 135 and 136.

After that, the operator may pull the front panel 122 and thus draw theCD-ROM drive body 121 in the direction A₂. Thus, the rail members 131and 132 move in the direction A₂. As a result, the gears 137 and 138 arerotated and thus the coupling members 135 and 136 move in the directionA₂. A length for which each of the coupling members moves is half of alength for which each of the rail members 131 and 132 moves.

FIGS. 12 and 15 show a state in which the CD-ROM drive body 121 has beendrawn in the direction A₂ to the limit. In this state, each of thecoupling members 135 and 136 has moved in the direction A₂ for a lengthhalf of a length for which the CD-ROM drive body 121 has been drawn,that is, a length for which each of the rail members 131 and 132 hasmoved. The front end 135c of the coupling member 135 is located at aposition in proximity to the center of the rail member 131, and the rearend 135d of the coupling member 135 is located at a position inproximity to the center of the rail member 133, as shown in FIGS. 12 and15. Similarly, the front end 136c of the coupling member 136 is locatedat a position in proximity to the center of the rail member 132, and therear end 136d of the coupling member 136 is located at a position inproximity to the center of the rail member 134, as shown in FIGS. 12 and15.

Therefore, an approximately half length of the entire length of each ofthe sliding portions 135a and 135b of the coupling member 135 is fittedto a respective one of the rail members 133 and 135. Similarly, anapproximately half length of the entire length of each of the slidingportions 136a and 136b of the coupling member 136 is fitted to arespective one of the rail members 134 and 132.

Thus, even in the state in which the CD-ROM drive body 121 has beendrawn to the limit in the direction A₂, that is, in the state in whichthe CD-ROM drive body 121 has projected from the containing portion 112to the limit, the approximately half length of the entire length of eachof the rail members 131 and 132 is fitted to a respective one of thesliding members 135b and 136b. The rail members 131 and 132 are mountedon the CD-ROM drive body 121 as mentioned above. Similarly, theapproximately half length of the entire length of each of the railmembers 133 and 134 is fitted to a respective one of the sliding members135a and 136a. The rail members 131 and 132 are mounted in thecontaining portion 112 as mentioned above. In contrast to this, only anapproximately 10% of the entire length of each of the rail members 181and 182 shown in FIG. 3 is fitted to a respective one of the guides 175and 176 in the CD-ROM drive device in the related art. Thus, in theCD-ROM drive device in the second embodiment of to the presentinvention, a length in the directions A₁ and A₂ for which the CD-ROMdrive body 121 engages with the containing portion 112 is longer thanthat in the device in the related art. As a result, the above-describeddisadvantageous moving of the CD-ROM drive body 121 in the certainmanner with respect to the containing portion 112 can be greatlyprevented.

Assuming that, for example, a length for which the CD-ROM drive body 121has moved after it has been drawn in the direction A₂ from thecontaining portion 112 to the limit is 120 mm, it is possible to provideapproximately 70 mm of a length for which each of the coupling members135 and 136 is fitted to a respective one of the rail members 131, 132,133 and 134. As a result, it is possible to greatly reduce theabove-mentioned disadvantageous moving of the CD-ROM drive body 121 inthe certain manner. In fact, even in the state in which the CD-ROM drivebody 121 has projected from the containing portion 112 to the limit, amaximum possible length in the vertical directions Z₁ and Z₂ shown inFIGS. 11, 13, 15 and 16 for which the front end of the CD-ROM drive body121 moves with respect to the containing portion 112 is onlyapproximately 0.5 mm. Similarly, a maximum possible length for which thefront end of the CD-ROM drive body 121 moves with respect to thecontaining portion 112 in the left and right directions B₁ and B₂ shownin FIGS. 11, 12, 13 and 17 can be greatly reduced.

Further, in the embodiment of the present invention, as described above,the CD-ROM drive body 121 has the rail members 131 and 132 on both sidesthereof. Thus, the CD-ROM drive device has two sets of guidingmechanisms, one consisting of the rail members 131, 133 and the couplingmember 135 and the other consisting of the rail members 132 and 134 andthe coupling member 136. In comparison to a case in which only a singleguiding mechanism was provided, the provision of the two guidingmechanisms in the device in the embodiment of the present invention caneffectively reduce the above-mentioned disadvantageous moving of theCD-ROM drive body 121. In the two guiding mechanisms, the two couplingmembers 135 and 136 are aligned with each other along the directions B₁and B₂ while the CD-ROM drive body 121 is being projected from thecontaining portion 112 and simultaneously the coupling members 135 and136 are moving accordingly as described above. Therefore, theabove-mentioned disadvantageous moving of the CD-ROM drive device 121can be effectively reduced.

After the operator has drawn the CD-ROM drive body 121 from thecontaining portion 112 to the limit as described above, the operator maytake out the CD-ROM 151 which has been placed on the turn table 125 ofthe CD-ROM drive body 121, and then appropriately put another CD-ROM 151on the turn table 125 of the CD-ROM drive body 121.

If the operator wishes to cause the one drawn CD-ROM drive body 121 tobe contained in the containing portion 112, the operator may press theCD-ROM drive body 121 in the direction A₁ shown in FIG. 11. If theoperator has pressed the CD-ROM drive device 121 as mentioned above andthus the CD-ROM drive device 121 is in a state in which containing ofthe CD-ROM drive device 121 in the containing portion 112 is almostcompleted, the end of the engaging portion 142a of the locking arm 142comes into contact with the pin 155. The locking arm 142 is then rotatedclockwise and thus the engaging portion 142a₁ engages with the pin 55.Thus, the CD-ROM drive body 121 is locked in the containing portion 112and thus the containing of the CD-ROM drive body 121 in the containingportion 112 is completed.

The CD-ROM 151 placed on the turn table 125 is located, as shown inFIGS. 13 and 14, over the top plate 124 of the CD-ROM drive body 121 andis located in a height lower than a height in which the top ends of sidewalls 114 and 115 and a rear wall 113 of the containing portion 112shown in FIG. 12. Further as shown in FIGS. 11 and 13, a right end ofthe CD-ROM 151 juts rightward from an edge portion 116 provided at theright side of the containing portion 112.

The positions of the racks 132a and 134a of the rail members 132 and 134are not limited to those shown in FIG. 17. It is possible that, insteadof the structure shown in FIG. 17, the rack 132a is formed on the bottomedge portion 132a and the rack 134a is formed on the top edge portion134d. Similar modification can be also applied to the racks of the railmembers 131 and 133.

With reference to FIGS. 18 through 21, a CD-ROM drive device 201 (whichwill be simply referred to as a device, hereinafter) in a thirdembodiment of a disc device according to the present invention will nowbe described. The CD-ROM drive device 201 is a disc device which isincorporated into a frame of a notebook type personal computer (notshown in the figures).

The device 201 includes a tray 202 on which a disc will be placed, asub-chassis 203 (shown in FIG. 20) which supports the tray 202, a traysliding mechanism 204 which supports the tray 202 so that the tray 202can freely slide with respect to a chassis 210, an optical pick up unit205 provided on the sub-chassis 203, a turn table 206 for rotating thedisc (CD-ROM) placed on the turn table 206, a holding mechanism 207which holds the tray 202 when the tray 202 has moved to a discreplacement position, and a locking mechanism 208 which locks the tray202 when the tray has moved to a disc loading position.

FIG. 18 shows a state in which the tray 202 has moved to the discloading position. Further, FIG. 18 shows a state in which a top plate209 (shown in FIG. 20) has been removed for the sake of easydescription. In the disc loading position, the tray 202 is contained inthe device 201. FIG. 19 shows a state in which the tray 202 has moved tothe disc replacement position. Further, FIG. 19 shows a state in whichthe top plate 209 has been removed for the sake of easy description. Inthe disc replacement position, the tray 202 has projected from thedevice 201.

As shown in FIG. 22A, the tray 202 has a shape such that a right endpart of the disc D_(A) juts rightward from the tray 202. That is, awidth of the tray 202 measured along a direction perpendicular todirections A and B shown in FIG. 18 is shorter than an outer diameter ofthe disc. The tray 202 moves in either the direction A or the directionB between the disc replacement position and the disc loading position,as an operator manipulates the tray 202. Therefore, no driving mechanismis not provided such as that consisting of a motor and a powertransmission mechanism or the like for driving the tray 202 in thedirections A and B. As a result, a number of components included in thedevice 201 can be reduced and thus miniaturization and thinning of thedevice 201 can be achieved.

With reference to FIGS. 19 and 21, the chassis 210 includes a containingportion 210a for containing each component described above, and a coverportion 210b extending rightward so as to cover a bottom of theabove-mentioned jutted right end part of the disc and thus protect it.As shown in FIG. 19, a free space is present below the cover portion210b and at the right side of the containing portion 210a. This spacemay be used to contain any components included in the notebook typepersonal computer which incorporates the device 201.

A front bezel 211 is fixed on the front end of the tray 202 and thusslides with respect to the chassis 210 in the directions A and Btogether with the tray 202. A switch button 212 is provided at thecenter of the front bezel 211 and is used to release locking which isperformed by the locking mechanism 208, the releasing being performed soas to allow the tray 202 to be drawn. If the switch button 212 ismanipulated in an ON manner when the device 201 is in the state shown inFIG. 18, the tray 202 automatically projects from chassis 210, as willbe described later, and thus the front bezel 211 projects forapproximately 5 through 10 mm forward in the direction A. As a result,it is easy for the operator to pull the tray 202.

As shown in FIGS. 20, 22A and 22B, the tray 202 includes a disc facingportion 202a which consists of a plane surface for facing a disc planesurface and forming a space thereon, the space receiving the disc. Anopening 202b is formed in the disc facing portion 202a and is used forthe pick up and the turn table. Further, another opening 202c is formedfor an operator to insert the operator's finger and to pick up the discplaced on the disc facing portion 202a of the tray 202.

A dimension of the disc facing portion 202a measured along a directionperpendicular to the directions A and B is slightly smaller than thewidth of the containing portion 210a measured along the directionperpendicular to the directions A and B. However, almost all length ofthe width of the containing portion 210a is covered by the relevantdimension of the disc facing portion 202a. As shown in FIG. 22A, an areaof a combination of the disc facing portion 202a and the opening 202b isapproximately 2/3 of an area of a disc top surface. As mentioned above,the tray 202 has the shape such that the right end part of the discD_(A) juts rightward from the tray 202. That i8s, the right end part ofthe disc D_(A) juts from the right end of the disc facing portion 202a.

When an operator wishes to pick up the disc placed on the tray 202, theoperator may take the thus-jutted part of the disc with the operator'sfingers. Therefore, it is not necessary to provide a concavity in thetray 202 particularly for the operator to take the disc with theoperator's fingers. In the structure shown in FIG. 22A, the operator mayfreely use a space present at the right side of the tray 202 to take thedisc with the operator's fingers. Because a relatively large part of thedisc juts from the right end of the tray 202 as shown in FIG. 22A, theoperator may use any positions of the jutted part when the operatortakes the disc with the operator's fingers. Thus, the operator caneasily and also surely pick the disc up from the tray 202. When theoperator picks up the disc with the operator's fingers, the operatortakes the jutted right side part of the disc with fingers of theoperator's right hand, and inserts a finger of the operator's left handinto the opening 202c, thus hooking the left end of the disc with thefinger of the left hand.

As shown in FIG. 22A, the opening 202c is formed at a portion of thetray 202 near to a corner thereof but not at a portion thereof near tothe left end of the disc facing portion 202a. Thus, the provision of theopening 202c does not cause the width, in the horizontal direction inFIG. 22A, of the tray 202 to be wider. As a result, the horizontaldirection width of the tray 202 can be further reduced, greatminiaturization of the tray 202 being thus achieved. Therefore,miniaturization of the device 201 can be achieved. In fact, a relevantwidth of the containing portion 210a can be reduced accordingly.

With reference to FIGS. 20, 23A, 23B and 23C, the sub-chassis 203includes a square-shaped frame 203a on which the tray 202 is placed andfixed, the frame 203a having an opening for the pick up and turn table.The sub-chassis 203 further includes a bracket 203b extending along thedirections A and B and provided at a right side wall of the frame 203a.The sub-chassis 203 further includes a guide rail pulling member 214screwed on a left side wall 203c of the frame 203a. The guide railpulling member 214 has a pair of pulling portions 214a and 214b upwardprojecting from the frame 203a. Further, the frame 203a is provided witha mounting portion 246 for mounting an extending member 249 whichsupports an ejecting pushing member 248 shown in FIG. 42 as will bedescribed later. The frame 203a is further provided with a screw hole203e to be used to screw a base 222 via vibration absorbing members 255.

With reference to FIGS. 20, 21, 24, 25, 26, and 27, the tray slidingmechanism 204 has a pair of guide rail mechanisms 215 and 216 mounted onboth sides of the sub-chassis 203.

Each of the guide rail mechanisms 215 and 216 includes a moving rail 217fixed on the bracket 203b of the sub-chassis 203, a static rail 218extending in parallel to the movable rail 217, a sliding rail 219present between the moving rail 217 and the static rail 218 and engagingwith the rails 217 and 218 in a manner in which the sliding rail 219 isslidable on each of the rails 217 and 218.

Each rail of the moving rail 217 and the static rail 218 has a crosssectional shape like an angular letter "C" as shown in FIGS. 21 and 25.Each of the rails 217 and 218 has a respective one of edge portions 217aand 218a formed thereon as a result of bending ends of the rails so asto approach each other. The edge portion 217a is a bottom edge portionof the moving rail 217 and is provided with a rack gear 217b formedtherein extending along a longitudinal direction of the rail. The edgeportion 218a is a top edge portion of the static rail 218 and isprovided with a rack gear 218b formed therein extending along thelongitudinal direction of the rail.

As shown in FIGS. 21 and 25, the sliding rail 219 has a cross sectionalshape like a letter "H". The sliding rail 219 has a first track 219awith which the edge portion 217a of the moving rail 217 engages, and asecond track 219b with which the edge portion 218a of the static rail218 engages, and a groove 219c present between the first and secondtracks 219a and 219b. A pinion gear 220 is contained in the groove 219cat the center on the longitudinal direction. The pinion gear 220 issupported in the sliding rail 219 in a manner in which the pinion gear220 is rotatable. Each one of the rack gears 217b and 218b of the movingand static rails 217 and 218 engages with a respective one of a top endportion and a bottom end portion of the pinion gear 220.

As shown in FIG. 25, the static rail 218 of the guide rail mechanism 215is screwed on a right side wall 210d of the chassis 210. The moving rail217 is screwed on the bracket 203b of the sub-chassis 203 which supportsthe tray 202. When the tray 202 is drawn by an operator in the directionA shown in FIG. 19, as shown in FIG. 27, the moving rail 217 slides onthe sliding rail 219 in the direction A and simultaneously the piniongear 220 is rotated due to this sliding. Further, as the pinion gear 220is thus rotated, simultaneously, the sliding rail 219 slides on thestatic rail 218 in the direction A.

Further, as shown in FIGS. 25, 28A, 28B and 28C, the moving rail 217 ofthe other guide rail mechanism 216 is screwed on the pulling portions214a and 214b of the guide rail pulling member 214 formed on thesub-chassis 203. Each of the pulling portions 214a and 214b was formedas being cranked as shown in FIG. 28A and thus acts as a leaf spring.The moving rail 217 was screwed on each of the pulling portions 214a and214b so that the portion 214a and 214b were deformed. This deformationof the portions 214a and 214b was such that, due to resulting elasticrestoration force of the pulling portions 214a and 214b acting as theleaf springs, the portions 214a and 214b always pull the moving rail 217in a direction X shown in FIGS. 28A and 28B perpendicular to thedirections A and B being sliding directions. This always pullingprevents the tray 202 from possibly disadvantageously moving inhorizontal directions perpendicular to the directions A and B shown inFIG. 19. The static rail 218 of the guide rail mechanism 216 is screwedon a left side wall 210c of the chassis 210 shown in FIG. 25.

As shown in FIGS. 28A and 28B, when the moving rail 217 is pulled in thedirection X, a first gap S1 is formed between the moving rail 217 andthe static rail 218. Further, at the same time, a second gap S2 shown inFIG. 28A is formed between the static rail 218 and the second track 219bof the sliding rail 219. Further, at the same time, a third gap S3 shownin FIG. 28A is formed between the moving rail 217 and the first track219a of the sliding rail 219. Due to the gaps S1, S2 and S3 thus-formedbetween the rails 217, 218 and 219 of the guide rail mechanism 216,sliding friction between the rails 217, 218 and 219 can be reduced.Thus, the guide rail mechanism 216 supports the tray 202 in a manner inwhich the tray 202 is slidable with the reduced sliding friction. Andalso the possible disadvantageous movement of the tray 202 in thehorizontal directions perpendicular to the directions A and B shown inFIG. 19 can be prevented, even during the sliding of the tray 202, dueto the pulling force in the direction X by means of the pulling portions214a and 214b. Therefore, the tray 202 can move in the directions A andB easily and smoothly.

Further, the sliding rail 219 is provided between the static rail 218and the moving rail 217 as described above with engagement between thepinion gear 220 and each of the rack gears 218b and 217b. The slidingrail 219 is slidable on each of the rails 217 and 218. As a result, themoving rail 217 can move in a direction of the directions A and B for alength twice a length for which the sliding rail 219 moves in the samedirection. Therefore, the guide rail mechanisms 215 and 216 provide anappropriate length for which the tray 202 can move between theabove-mentioned disc loading position and the disc replacement position.The guide rail mechanisms 215 and 216 guide the movement of the traywhile the tray 202 moving for the above-mentioned appropriate length.Further, the possible disadvantageous movement of the tray 202 in thehorizontal directions perpendicular to the directions A and B shown inFIG. 19 can be prevented, while the tray 202 moving for theabove-mentioned appropriate length, due to the pulling force applied tothe moving rail 217 in the direction X by means of the pulling portions214a and 214b. Therefore, the tray 202 can be drawn in the direction Aeasily and smoothly.

Accordingly, the tray 202 moves with respect to the chassis 210 in thedirections A and B stably. As a result, vibration transmitted from thetray 202 to the turn table 206 and the pick up unit 205 shown in FIG. 19can be reduced. Thus, degradation of an accuracy in detectinginformation through the pick up unit 205 can be prevented, whichinformation was recorded on the disc, the disc being rotated by the turntable 206.

Thus, the tray 202 is guided by the guide rail mechanisms 215 and 216 ina manner in which the tray 202 can slide in the directions A and B. Asshown in FIG. 25, the left guide rail mechanism 216 is provided betweenof the left side of the sub-chassis 203 and the left side wall 210c ofthe chassis 210. The right guide rail mechanism 215 is provided betweenof the right side of the sub-chassis 203 and the right side wall 210d ofthe chassis 210. When the tray 202 is located in the disc loadingposition as shown in FIG. 18, the rails 217, 218 and 219 of the guiderail mechanisms 215 and 216 are contained in the chassis 210. When thetray 202 is dawn in the direction A and thus moves up to the discreplacement position as shown in FIG. 19, as shown in FIG. 27, thesliding rail 219 moves for a length L with respect to the static rail218 in the direction A. At the same time, the moving rail 217 moves forthe same length L in the direction A.

Further, as shown in FIGS. 19, 20, 25, and 29, a driving unit 221 isprovided over the sub-chassis 203 and includes the pick up unit 205 andthe turn table 206. The driving unit 221 further includes a base 222mounted on the sub-chassis 203. The pick-up unit 205 and the turn table206 are mounted on the base 222. The driving unit 221 further includes apick up driving unit 223 for moving the pick up unit 205 along a pick upmoving direction radially extending from a rotation axis of the discplaced on the turn table 206.

Further the tray 202 is mounted on the base 222 and the vibrationabsorbing members 255 is provided between the sub-chassis 203 and thebase 222, the members 255 absorbing vibration. Vibration occurring inthe sub-chassis 203 is absorbed by the vibration absorbing member 255.As a result, possible vibration occurring in the sub-chassis 203 whenthe tray 202 moves through the guide rail mechanisms 215 and 216 isabsorbed by the vibration absorbing member 255. Thus, the possiblevibration is reduced when the vibration has been transmitted to the pickup unit 205 and the turn table 206 via the vibration absorbing members255 and the base 222.

As shown in FIG. 29, the pick up driving unit 223 includes a pick updriving motor 224 provided on a bottom surface of the base 222, a powertransmission mechanism 225 including a plurality of gears, a lead screw226 extending along the above-mentioned pick up moving direction andbeing turned via the power transmission mechanism 225, and a guide shaft227 extending in parallel to the lead screw 226 and guiding the movementof the pick up unit 205. An opening 222a is formed in the base 222 so asto extend along the pick up moving direction. The pick up unit 205 issupported by the lead screw 226 and the guide shaft 227 at both sides ofthe pick up unit 205. The pick up unit 205 has an engaging portion 228which engages with screw threads formed on the lead screw 226. Further,the guide shaft 227 supports the pick up unit 205 so that the pick upunit 205 is slidable on the guide shaft 227. Therefore, the pick up unit205 moves along the pick up moving direction in response to the turningof the lead screw 226, the turning of the lead screw 226 resulting fromthe pick up driving motor 224 driving the lead screw via the powertransmission mechanism 225. While the pick up unit 205 is thus movingalong the pick up moving direction, the pick up unit 205 is exposed viathe opening 222a extending along the pick up moving direction.

The turn table 206 has a turn table driving motor 229 at the bottomthereof. The turn table driving motor 229 starts turning when the tray202 has reached the disc loading position in the device 201. Thus, themotor 229 rotates the disc which was previously clamped on the turntable 206 which thus is being rotated at a fixed rotation speed.

As shown in FIGS. 31A and 31B, the opening 222a formed in the base 222has a shape not only such that the pick up unit 205 is exposed asdescribed above but also such that the turn table 206 projecttherethrough. Further, as shown in FIGS. 32A and 32B, on the bottomsurface of the base 222, there are provided a turn table mountingportion 222b on which the turn table 206 is mounted and a pick updriving unit mounting portion 222c on which the pick up driving unit 223driving the pick up unit 205.

Further, the base 222 has three mounting portions 222d, 222e and 222fprovided in the edge thereof as shown in FIG. 32B, these three mountingportions being used for mounting the base 222 on the sub-chassis 203. Asshown in FIGS. 32A and 32B, each of the three mounting portions 222d,222e and 222f has a letter "U" shape and is formed to be thinner thananother portion surrounding the mounting portion so that the vibrationabsorbing members 255 can be inserted from the side and thus they can beinstalled to the mounting portions 222D, 222e and 222f.

Each of the vibration absorbing members 255 is made of one piece ofelastic rubber, and, as shown in FIG. 33, has a neck portion 255a, afirst damper 255b above the neck portion 255a and a second damper 255cbelow the neck portion 255a. The neck portion 255a has an outer diametershorter than each of outer diameters of the first and second dampers255b and 255c, as shown in the figure. Further, generally, each of thevibration absorbing members 255 has a hollow tube shape having a throughhole 255d.

The top end and bottom end of each of the dampers 255b and 255c comeinto contact with the surface of a screw 256 over the entirecircumference thereof as shown in FIG. 33, the screw 256 having beeninserted into the through hole 255d. As a result, as shown in thefigure, the dampers 255b and 255c form ring-shaped closed air spaces255e and 255f between the inner surfaces of the dampers and the surfaceof the screw 256, respectively. Due to the provision of the closed airspaces 255e and 255f, each of the vibration absorbing members 255 formsan air spring.

The neck portions 255a of the vibration absorbing members 255 are fittedto the mounting portions 222d, 222e and 222f from the side. Then, a mailthread 256a of the screw 256 is inserted into the through hole 255d ofeach of the vibration absorbing members 255, and then is screwed in theabove-mentioned screw hole 203e of the sub-chassis 203. Thus, the base222 is fixed on the sub-chassis 203 via the vibration absorbing members255.

As shown in FIG. 33, the screws 256 do not come into direct contact withthe base 222 because the vibration absorbing members 255 are insertedbetween the base 222 and the screws 256. Therefore, vibration isprevented from being transmitted from the sub-chassis 203 to the base222 via the screws 256. As shown in the figure, the head 256a of eachscrew 256 fastens a respective one of the mounting portions 222d, 222eand 222f of the base 222 to the sub-chassis 203 via the first damper255b. Thus, the base 222 is flexibly supported on the sub-chassis 203due to the vibration absorbing members 255. And thus, vibrationoccurring in the sub-chassis 203 in any possible direction can beabsorbed by the vibration absorbing members 255. As a result, ifvibration occurs in the sub-chassis 203 when the tray 202 moves in thedirections A and B shown in FIGS. 18 and 19, the pick up unit 205 andturn table 206 mounted on the base 222 is prevented from being affectedby the vibration. Thus, an accuracy in detecting data recorded in thedisc through the pick up unit 205 is prevented from being degraded.

It is assumed that the disc is clamped on the turn table 206. The turntable 206 projects from the tray 202 as shown in FIG. 18 and thus thebottom surface of the disc clamped on the turn table 206 is spaced fromthe top surface of the tray 202. The turn table 206 on which the dischas been thus clamped is mounted on the base 222 as mentioned above andalso the tray 202 is directly mounted on the base 222. As a result, thedisc is constructively strongly related to the tray 202 via the turntable 206 and the base 222. If relatively large magnitude vibrationoccurs in the sub-chassis 203, the vibration absorbing members 255 islargely elastically deformed. Resulting vibration of the base 222 isunavoidable from occurring. Because the disc is constructively stronglyrelated to the tray 202 via the turn table 206 and the base 222 asmentioned above, possible large elastic deformation of the vibrationabsorbing members 255 results in occurrence of corresponding vibrationin the disc via the base 222 and the turn table 206 and also results inoccurrence of the identical vibration in the tray 202 via the base 222.Because the disc and tray 202 vibrate identically as mentioned above,the disc is prevented from coming into contact with the tray 202. Thus,the disc is prevented from being damaged due to coming into contact withthe tray 202.

Conventionally, such a disc device has a structure such that a distancebetween the disc and tray may be approximately 5 mm in order to preventthe disc from coming into contact with the tray when the disc vibrates.In contrast to this, in the third embodiment of the present invention,as shown in FIG. 34, it is possible that a distance L_(A) between thedisc D_(A) clamped on the turn table 206 and the disc facing portion202a of the tray 202 is shortened to be approximately 1 mm. As a result,it is possible to make the disc device 201 be thinner.

A structure of the top plate 209 shown in

FIG. 20 will now be described. As shown in FIGS. 34, 35 and 36, the topplate 209 has an opening 209a at a position which, when the tray 202 islocated in the above-mentioned disc loading position, a top portion ofthe turn table 206 faces. The opening 209a is covered by a lid 257having a thickness t_(b) thinner than a thickness t_(a) of approximately1 mm of the top plate 209a. The thickness t_(b) of the lid 257 isapproximately 0.2 mm and thus approximately 1/5 of the thickness t_(a)of the top plate 209a.

In the structure of the disc device 201, it is possible to position thetop plate 209 as low as possible in which the lid 257 does not come intocontact with the turn table 206. As a result, it is possible to make thedisc device 201 be thinner. When the tray 202 moves in the direction A,the top portion of the turn table 206 slides on the bottom surface ofthe top plate 209.

The edge of the lid 257 is placed on a mounting portion 209b providedaround the opening 209a. The lid 257 has a shape similar to a shape ofthe opening 209a and has three holes 257a in the edge thereof. Themounting portion 209b has three bosses 209c which are shaped andpositioned so as to match the three holes 257a of the lid 257 when theedge of the lid is placed on the mounting portion 209b. The bosses 209care inserted into the holes 257a respectively and then the top of eachof the bosses 209c is deformed. Thus, the edge of the lid 257 is fixedon the mounting portion 209a. The top surface of the mounting portion209b is lower than the top surface of a portion around the mountingportion 209b in the top plate 209 as shown in FIG. 36. Thus, it ispossible that the top surface of the lid 257 fixed on the top plate 209is horizontally aligned with the top surface of the surrounding portionof the top plate 209.

Further, in the lid 257 ,a letter "U"-shaped reinforcement rib 257b isformed and further a long circle-shaped protrusion 257c is formed, asshown in FIGS. 35 and 36. The top portion of the turn table 206 slideson the protrusion 257c and, as shown in FIG. 36, the protrusion 257c hasa smoothly arc-shaped cross sectional shape. When the tray 202 moves inthe direction A, the bottom surface of the protrusion 257c graduallypresses the top portion of the turn table 206 downward and thus the turntable 206 is lowered as shown in FIG. 37.

The lowering of the turn table 206 is allowed as a result of the firstand second dampers 255b and 255c of each of the vibration absorbingmembers 255 shown in FIG. 33 being deformed as the closed air spaces255e and 255f are compressed vertically. As a result, the turn table 206can smoothly slide on the top plate 209 when the tray 202 moves in thedirection A. Because a portion at which the top plate 209 comes intocontact with the top portion of the turn table 206 is limited on theprotrusion 257c while sliding, friction between therebetween can bereduced.

As mentioned above, the holding mechanism 207 which the tray 202 whenthe tray 202 has moved to a disc replacement position. As shown in FIG.38, the holding mechanism 207 includes a first holding member 231located at the top right in FIG. 38 and a second holding member 233located at the bottom left in the figure. As shown in FIG. 39B, Thefirst holding member 231 engages with a holding hole 30 formed in thechassis 210 when the tray 202 has moved to the disc replacementposition. Thus, the tray 202 is held there. As shown in FIG. 40C, thesecond holding member 233 engages with a cut-out portion 202g formed inthe tray 202 when the tray 202 reaches the disc replacement position.Thus, the tray 202 is held there.

As shown in FIGS. 39A and 39B, the first holding member 31 is providedon a end portion of the bracket 203b of the sub-chassis 203. The firstholding member 31 includes a leaf spring 231a fixed, with rivets 234, onthe bottom surface of the end portion of the bracket 203b, and a holdingportion 231b provided on the projecting end of the leaf spring 231a. Theholding portion 231b has a sliding surface 231c for sliding on thechassis 210, a holding surface 231d for being held in a holding hole 230of the chassis 210, and an inclined surface 231e used when the holdingportion 231b is removed from the holding hole 230. As shown in FIG. 21,the holding hole 230 is located at a position near this end and near theright end of the containing portion 210a.

Before the tray 202 has reached the disc replacement position, as shownin FIG. 39A, the sliding surface3 231c of the holding portion 231b ofthe first holding member 231 slides on the chassis 210 and the leafspring 231a is bent in a direction C. The bending of the leaf spring231a causes the sliding surface 231c of the holding portion 231b to bepressed onto the chassis 210. This results in a reaction in which thesub-chassis 203 is pressed upward in FIG. 39A by the leaf spring 231a.Thus, the tray 202 mounted on the sub-chassis 203 is prevented fromdisadvantageously moving vertically in FIG. 39A. The holding portion231b is made of synthetic resin and thus friction resistance due to thesliding of the holding portion 231b on the chassis 210 is relativelysmall. Thus, friction between the sliding surface 231c and the chassis210 while sliding is reduced and the tray 202 may smoothly move in thedirection A.

When the tray 202 reaches the disc replacement position, as shown inFIG. 39B, the holding portion 231b enters the holding hole 230 as theholding portion 231b moves in a direction D. Thus, the holding surface231d comes into contact with the left edge, in FIG. 39B, of the hole230. Due to the engagement of the holding surface 231d with the edge ofthe hole 230, the tray 202 on the sub-chassis 203 is prevented frombeing further moved in the direction A.

When the tray 202 moves in the direction B, the inclined surface 231e ofthe holding portion 231b runs on the right edge, in FIG. 39B, of thehole 230, as shown in the figure. Thus, the holding portion 231b movesin a direction C and thus the holding portion 231b is completely removedfrom the hole 230. As a result, the tray 202 can further move in thedirection B as the holding portion 231b slides on the chassis 210 asshown in FIG. 39A.

Thus, the engagement of the holding portion 231b of the first holdingmember 31 with the holding hole 230 limits the movement of the tray 202with respect to the chassis 210 in the direction A and allows themovement thereof in the direction B.

As shown in FIGS. 40A, 40B and 40C, the second holding member 233includes a roller 235 for rolling on a side wall 202e of the tray 202,and a roller supporting member 236 for supporting the roller 235 in amanner in which the roller is rotatable. The roller 235 rolls on theside wall 202e of the tray 202 as the tray 202 moves in the directions Aand B. The roller 235 enters the cut-out portion 202g formed in the sidewall 202e when the tray 202 reaches the disc replacement position, andthe roller 235 enters a cutout portion. 202f also formed in the sidewall 202e. As a result of the roller 235 entering the cut-out portions202g as shown in FIG. 40C, the movement of the tray 202 in the directionA is restricted. As a result of the roller 235 entering either of thecut-out portions 202g and 202f, the movement of the tray 202 in thedirection B is restricted. As shown in FIG. 22A, the cut-out portion202f is located at this side and the left side of the tray 202, and thecut-out portion 202g is located at the other side and the left sidethereof.

As shown in FIG. 40A, one end 236a of the roller supporting member 236is fixed on the this side of a left side wall 210d of the chassis 210with rivets 237. An arm portion 236b extends from the end 236a and theextending end 236c has the roller 235 supported thereon. The arm portion236b acts as a leaf spring for causing the roller 235 to press side wall202e of the tray 202 in a direction E. Thus, the tray 202 is preventedfrom disadvantageously moving horizontally in FIG. 40B. When the tray202 reaches the disc loading position, as shown in FIG. 40A, the roller235 enters the cut-out portion 202f because the leaf spring function ofthe arm portion 236b moves the roller 235 in the direction E. Thus, themovement of the tray 202 in the direction A is restricted. Similarly,when the tray 202 reaches the disc replacement position, as shown inFIG. 40C, the roller 235 enters the cut-out portion 202g because theleaf spring function of the arm portion 236b moves the roller 235 in thedirection E. Thus, the movement of the tray 202 in the direction B isrestricted. If an operator applies a force to the tray 202, which forcemay overcome the elastic force of the leaf spring function of the armportion 236b, it is possible to move the tray 202 either in thedirection A from the disc loading position or in the direction B fromthe disc replacement position. In fact, the operator's force bends thearm portion 236b in a direction F and thus causes the roller 235 to runon an edge of either of the cut-out portions 202g and 202f. Thus, theroller 235 is removed from either of the cut-out portions 202f and 202gand thus the tray 202 then may smoothly move as the roller 235 rolls onthe side wall 202e of the tray 202 as shown in FIG. 40B.

As shown in FIG. 24, the above-mentioned locking mechanism 208 islocated at a corner of the sub-chassis 203, the corner being located atthe bottom right in FIG. 24 of the sub-chassis 203. The lockingmechanism 208 includes a locking lever 239, which is mounted on amounting portion 245a of the frame 203a of the sub-chassis 203 and isheld by a holding roller 238 provided on a bottom portion 210f of thechassis 210. The locking mechanism 208 further includes a solenoid 242which is mounted on a mounting portion 245b of the frame 203a of thesub-chassis 203 and drives the locking lever 239 to rotate between alocking position and a locking releasing position. As shown in FIG. 41,the locking lever 239 includes a bearing portion 239a fitted to a shaft241 standing on the frame 203a, an arm 239c having a nail portion 239bat a free end thereof, which portion 239b engages with the holdingroller 238, and a linking arm 239d linked with a plunger 243, whichplunger is driven by the solenoid 242. An projecting end of the plunger243 passes through a hole 239e formed in the linking arm 239d as shownin FIG. 41 and thus is linked with the locking lever 239.

The locking lever 239 has a torsion spring (not shown in the figures)which applies a force to the locking lever 239 and thus the lever 239moves in a direction G shown in FIG. 41. As a result, the nail portion239b of the lever 239 engages with the holding roller 238 and thus thelocking lever 239 locks the sub-chassis 203 to the chassis 210. Then, ifthe above-mentioned switch button 212 of the front bezel 211 ismanipulated in an ON manner, the solenoid 242 is energized and thusabsorbs the plunger 243. When the solenoid 242 is energized as mentionedabove, the plunger 243 pulls the linking arm 239d as a result of movingdue to electromagnetic force of the solenoid 242. As a result, the lever239 is rotated in a direction H about the shaft 241 and thus the nailportion 239b is disengaged from the holding roller 238. Thus, the lever239 release the locking of the sub-chassis 203 with the chassis 210.

The above-mentioned extending member 249 is mounted on the mountingportion 246 of the frame 203a of the sub-chassis 203a, the portion 246being located at the top left in FIG. 23A of the sub-chassis 203. Asshown in FIG. 42, the above-mentioned ejecting pushing member 248 has along hole 248a formed therein, and a pin 249a stands on the extendingmember 249. The pin 249a of the extending member 249 is inserted intothe long hole 248a of the ejecting pushing member 248. Further, a spring247 is provided, one end thereof is held to a holding portion 249bformed at the top left, in FIG. 42, of the extending member 249, and theother end is held by a bottom left portion (not shown in the figure) ofthe ejecting pushing member 248. As a result, elasticity of the spring247 applies a pulling force to the ejecting pushing member 248 to causethe ejecting pushing member to move in the direction B.

When the tray 202 is located in the disc loading position as shown inFIG. 38, the ejecting pushing member 248 is pressed onto a rear wall210g of the chassis 210. Thus, as shown in FIG. 38, the ejecting pushingmember 248 moves in the direction B with respect to the extending member249 mounted on the sub-chassis 203, and thus the elasticity of thespring 247 causes the ejecting pushing member 248 to push the rear wall210g of the chassis 210. Therefore, when the locking of the sub-chassis203 with the chassis 210 is released as mentioned above, the pushingforce of the ejecting pushing member 248 to the rear wall 210g of thechassis 210 results in a reaction in which the sub-chassis 203 moves inthe direction A.

Accordingly, the tray 209 mounted on the sub-chassis 203 moves in thedirection A and thus the front bezel 211 projects from the front surfaceof the notebook type personal computer, not shown in the figures, inwhich the disc device 201 is incorporated. Thus, the operator can easilypull the front bezel 211 and thus draw the tray 202. As a result of theoperator pulling the front bezel 211 and thus drawing the tray 202 inthe direction A by the operator's hand, the tray 202 reaches the discreplacement position as shown in FIG. 19.

A circuit substrate 251 shown in FIG. 21 is mounted on the bottomsurface of the tray 202 and drives and controls each portion of theabove-described driving unit 221. The circuit substrate 251 is connectedto the pick up unit 205, the turn table 206, and the pick up drivingmotor 224 of the driving unit 221, and is connected to, via flexiblecable 252a and 252b shown in FIGS. 19 and 42, to an externallyconnecting substrate 253. The circuit substrate 251 provides controlsignals to the pick up unit 205, the turn table 206, and the pick updriving motor 224 of the driving unit 221, which thus performpredetermined operations. The flexible cable 252a is located between thesub-chassis 203 and a right side wall of the containing portion 210a ofthe chassis 210 where the flexible cable 252a is slackened to be letter"U"-shaped. Thus, the flexible cable 252a does not prevent the tray 202from smoothly moving with respect to the chassis 210.

Performance of the above-described CD-ROM drive device 201 will now bedescribed.

When the tray 202 is contained in the device 201 as shown in FIGS. 18,29, and 38, as shown in FIG. 24, the locking lever 239 mounted on thesub-chassis 203 is held by the holding roller 238 of the chassis 210.Thus, the locking mechanism 208 locks the tray 202 and the sub-chassis203 in the disc loading position in the device 201. Further, as shown inFIG. 40A, the roller 235 of the holding member 233 is fitted into thecut-out portion 202f of the tray 202 so that the tray 202 resists movingin the direction A.

In response to the switch button 212 of the front bezel 211 beingmanipulated in the ON manner, with reference to FIG. 24, theelectromagnetic force of the solenoid 242 pulls the plunger 243 to theinside of the solenoid 242. As a result, the locking lever 239 isrotated in the direction H about the shaft 241 and thus the nail portion239b disengages from the holding roller 238. Thus, the locking of thetray 202 with the sub-chassis 210 in the disc loading position isreleased. As a result, with reference to FIG. 38, the elasticity of thecoil spring 247 causing the ejecting pushing member 248 to push the rearwall 210g of the chassis 210 results in the reaction of the sub-chassis203 together with the tray 202 moving the direction A.

With reference to FIGS. 40A and 40B, the roller 235 of the holdingmember 233, which has been fitted into the cut-out portion 202f of thetray 202 as show in FIG. 40A, rolls on an inclined portion of thecut-out portion 202f, as the ejecting pushing member 248 pushes the rearwall 210g of the chassis 210 and thus the sub-chassis 203 together withthe tray 202 moves in the direction A. As a result, the roller 235 rollsthe side wall 202e of the tray 202 as shown in FIG. 40B. Thus, thesub-chassis 202 and tray 203 automatically move in the direction A andthus the front bezel 211 projects from the front surface of the notebooktype personal computer for a predetermined distance. Therefore, theoperator can easily handle and pull the front bezel 211. As the frontbezel 211 is pulled by the hand of the operator in the direction A, themoving rail 217 of each of the above-described pair of guide railmechanisms 215 and 216 slides on the sliding rail 219 in the direction Aand simultaneously the sliding rail 219 slides in the static rail 218 inthe direction B, with reference to FIG. 27.

With reference to FIG. 37, while the tray 202 thus moves in thedirection A, the top portion of the turn table 206 is pressed down asthe top portion slides on the gentle slope of the projection 257c. Atthe same time, the first and second dampers 255b and 255c of thevibration absorbing members 255 shown in FIG. 33 are verticallycompressed as the turn table 206 is thus pressed down. Thus, the turntable 206 smoothly slide on the bottom surface of the top plate 209.

Thus, when the front bezel 211 is further pulled in the direction A, thesub-chassis 203 and the tray 202 move as the pair of the guide railmechanisms 215 and 216 guide the movement of the tray and sub-chassis.During the movement in the direction A, the roller 235 of the holdingmember 233 is continuously pressed onto the side wall 202e of the tray202. Thus, a possible disadvantageous movement of the tray in horizontaldirections perpendicular to the direction A is prevented and thus thetray can move stably. Further, the above-described guide rail pullingmember 214 continuously pulls the moving rail 217 in the direction Xshown in FIG. 28A. Thus, a possible disadvantageous movement of the trayin the horizontal directions perpendicular to the direction A isprevented and thus the tray can move stably.

When the tray 202 reaches the disc replacement position as shown inFIGS. 19 and 42, the roller 235 of the holding member 233 is fitted intothe cut-out portion 202g of the tray 202 shown in FIG. 40C. This beingfitted of the roller 235 into the cut-out portion 202g is accompaniedwith a click like feeling which may perceived by an operator who hasmoved the tray 202 until this time. Simultaneously, as shown in FIG.39B, the holding portion 231b of the holding member 231 is fitted intothe holding hole 230 as moving in the direction D, and thus the holdingsurface 231d comes into contact with the vertical edge wall of theholding hole 230. Thus, the tray 202 is locked in the disc replacementposition and thus further movement of the tray 202 in the direction A isprevented. Thus, the being fitted of the roller 235 of the holdingmember 233 into the cut-out portion 202g of the tray 202 provides theclick like feeling to the operator, who has been pulling the front bezel211 in the direction A, when the tray 202 is locked. Therefore theoperator can effectively recognize the locking and thus the operator isprevented from further pulling the front bezel 211. As a result, thetray 202 is prevented from being further pulled so as to be completelyremoved from the chassis 210. Further, it is also prevented that theoperator may stop pulling the front bezel 211 even before the tray 202has not reached the disc replacement position yet.

After the tray 202 has been locked in the disc replacement position asmentioned above, if a disc has been placed on the turn table 202, theoperator may remove the disc from the turn table 206. The tray 202 has astructure such that the disc D_(A) has been placed on the turn table 206in a state in which the right part of the disc D_(A) extends from theright edge of the tray 202 as shown in FIG. 22A. Therefore, the operatorcan hold the disc D_(A) by the operator's hand from any direction andcan hold any portion of the disc. Thus, it is easy for the operator tosurely take the disc out from the tray 202.

After that, the operator may put a new disc on the turn table 206 andthen may push the front bezel 211 in the direction B. By this pushing ,the roller 235 of the holding member 233 rolls on the inclined edge ofthe cut-out portion 202g shown in FIG. 40C. As a result, the roller 235rolls on the side wall 202e as shown in FIG. 40B. Simultaneously, theinclined surface 231e of the holding portion 231b of the holding member231 slides on the edge (located at the right side in FIG. 39B) of theholding hole 230 and thus moves in the direction C shown in FIG. 39B.Thus, the locking of the tray 202 in the disc replacement position isreleased.

After that, as the operator further pushes the front bezel 211 in thedirection B, the tray 202 moves in the direction B as being guidedthrough the pair of guide rail mechanisms 215 and 216. As a result, thetray 202 reaches the disc loading position shown in FIGS. 18, 29, and38. Same as the tray 202 moves in the direction A as described above,while the roller 235 of the holding member 233 rolls on the side wall202e of the tray 202, the roller 235 continuously presses the tray 202.Thus, a possible disadvantageous movement of the tray in the horizontaldirections perpendicular to the direction B is prevented and thus thetray can move smoothly and stably.

When the tray 202 reaches the disc loading position, the roller 235 ofthe holding member 233 is fitted into the cut-out portion 202f of thetray 202, as shown in FIG. 40A, with a click like feeling beingperceived by the operator who has been pushing the front bezel 211.Simultaneously, as shown in FIG. 24, the locking lever 239 of thelocking mechanism 208 is held by the holding roller 238 of the chassis210. Due the click like feeling perceived when the roller 235 is fittedinto the cut-out portion 202f, the operator may easily recognize, viathe operator's finger feeling, that the tray 202 has reached the discloading position.

Application of the present invention is not limited to a CD-ROM drivedevice such as that described above. The present invention may besimilarly applied to any device which handles disc (disk)-shapedrecording media such as CDs, magnetic disks, magneto-optical discs,optical discs.

Further, application of the present invention is not limited to a devicewhich is incorporated into a notebook type personal computer such asthat described above. The present invention may be applied to any devicewhich is incorporated into not only another electronic apparatus butalso another apparatus other than electronic apparatuses.

Further, application of the present invention is not limited to a devicein which the tray is moved by an operator's hand. The present inventionmay be applied to any device in which the tray is driven by drivingmeans such as an electric motor.

Further, application of the present invention is not limited to a devicein which the disc is placed on the tray. The present invention may beapplied to any device in which the disc is directly placed on the tray.

Thus, according to the above-described third embodiment of the presentinvention, the tray is fixed on the base, and the vibration absorbingmembers are provided between the sub-chassis and the base. The vibrationabsorbing members elastically supports the base and tray and thus absorbundesirable vibrations. Thus, not only the tray supporting the turntable and pick up device but also the base are elastically supported.Therefore, the disc clamped onto the turn table is prevented fromdisadvantageously coming into contact with the tray. As a result, it ispossible to have a structure in which a distance between the discclamped onto the turn table and the tray is reduced. Thus, the discdevice can be thinner.

Further, the tray has a structure such that the part of the disc extendsfrom the edge of the tray. Thus, an operator can easily hold theextending part of the disc and thus easily and surely take the disc outfrom the tray. Further, such a structure of the tray enables the chassisto be miniaturized and thus the disc device to be miniaturized.

Further, the present invention is not limited to the above-describedembodiments, and variations and modifications may be made withoutdeparting from the scope of the present invention.

What is claimed is:
 1. A disc device comprising:a turn table forrotating a disc; a disc motor for driving said turn table; a pick upunit for detecting information recorded in said disc; a tray for guidingan operator's placement of said disc appropriately on said turn table; asub-chassis provided with said turn table, disc motor, pick up unit andtray; wherein:said operator may move said tray between a disc loadingposition and a disc replacement position; and said sub-chassis isslidably supported on a chassis so that said tray may move between saiddisc loading position and said disc replacement position; a top platehaving a bottom surface for forming an enclosure with said chassiswithin which said tray is moved, said top plate having an opening in aposition in alignment with a position of said turn table with saidposition of said turn table being a position in a state where said trayis in said disc loading position; and a lid connected to said top platefor fixedly closing said opening, said lid having a bottom surfacealigned in a plane above the plane of the bottom surface of said topplate, with said lid having a thickness less than the thickness of saidtop plate, and with said turn table being able to extend into theopening in said top plate beneath said lid and above the plane of saidbottom surface of the top plate when said tray is in said disc loadingposition.
 2. The disc device as claimed in claim 1 further comprising:abase supported by said sub-chassis and supporting said pick up unit,turn table and disc motor, said tray being mounted on said base; and avibration absorbing member provided between said sub-chassis and saidbase for elastically supporting said base and said tray.
 3. The discdevice as claimed in claim 1 further comprising guide rails on oppositesides of said sub-chassis with said tray being movable along said guiderails between said disc loading position and said disc replacementposition.
 4. The disc device as claimed in claim 1 further comprising alocking mechanism for locking said tray when in said disc loadingposition.